In my honest opinion, there are 3 general ways to be rich or earn some serious money:

Generate Value

1. Solve people's problems and get paid solving it.Example is like GrabTaxi which solves the problem of hailing a cab and in the process creates a win-win situation for taxi drivers, consumers and the company itself. Simple idea but power business model.

Hourly maid business is booming because people just lazy/don't like to do housekeeping

2. Do something or a business people don't like to do- A blue ocean strategy because there is little or no competitor at all. E.g would be hourly maid, sewer cleaning. These are businesses people tend to shun away from because it is not glamorous, and in most cases, you as an entrepreneur of a small business might need to go hands-on.